Piston-ring



H. S. FRANK.

PISTON RING.

APPLICATION FILED pc.1. 191s.

Patented Dec. 20, 1921.

iiiiiiiiiiiiiiii will!" I l I I ma!!! isis!! HARRY S. FBNK, OF ST. LOUIS, MISSOURI.

Application filed December 7, 1918.

To all flo/tom t may concer/a Be it known that l. HARRY S. F RANK, a citizen o the United States, re 'ding at the city of St. Louis and State of ssouri, h are invented a new and useful Piston-Rino', oi which the following is a Specification.

rlhis invention relates to piston rings.

An object of the invention is to provide a novel and ellcient piston ring composed of a singjle piece of metal in the form ot two open bands, one ot which within the other, and which ring is capable of tree expansion and contraction in order to function properly as a piston ring.

Another object of the invention is to provide an improved piston ring olf the open resilient type composed of a plurality of coils one within the other and having integral connection whereby relative displacement of the coils is prevented.

Other objects of the invention will appear from the following; description in which reference is made to the accompanying drawings illustrating different forms ot the invention, and in which- Figure 1 is an elevation of a blank from which a ring` may be made.

Fig. 2 is an elevation of the blank after it has been cut to form a spiral element preparatory to the formation oi the ring.

Fig. 3 is an elevation of a finished ring made from the spiral element illustrated in Fig". 2.

Figs. 4;, 5 and 6 are elevations of modiiied forms of rings.

Fig. 7 is a side elevation ot the ring shown in Fig. 3.

Fig. 8 is a side elevation of another form of rino; which, viewed from another elevation, is the same as that illustrated in Fig. 3.

Fig. 9 is a side elevation of the types of rines illustrated in Figs. 5 and 6.

Figs. 10, 11 and 12 are views illustrating` different joints for the ends of the rings.

Fig. 13 is a cross sectional view on the line 1 3--13 of Fig. 7.

Fig". 14 is a cross sectional view on the line 1%-14 of Fig. 8.

Fig. 15 is a cross sectional view on the line 15-15 of Fig. 6.

Fig. 16 is a cross sectional view on the line 16-16 of Fig. 5.

Fig. 17 is a cross sectional view on the line 17-17 of Fig. 4.

`lin order to comprehend clearly the charf Specification of Letters Patent.

Patented Dec. 2&9, 1921.

Serial No. 265,721.

acteristios of my improved piston ring it is appropriate to refer briefly to the manner in which the ring may be made. rllhe manner in which the ring` may be made may be understood more clearly by makingreference to Figs. 1 rand 2 of the drawings, ln F ig. 1 a form of blank is shown for the manufacture of the ring shown in Figs. 3 and 'l'. It is unnecessary to illustrate the blanks for the construction of the other forms of rings shown in the drawing, since the manner in which they may be made from the blanks will be clearly understood from the description ot the manner in which any one form of the rings may be made.

As shown in F ig. 1 the blank is an integral element and in the manufacture of the ring the first step after the blank is obtained is the step o1c cutting or sawing the blank to provide a spiral element, one form of which is shown in Fig. 2. The cut or slot 1 which is formed is bontinuous so that the length oi the spiral element resulting from the formation ot the slot is almost double the circumference of the blank. rlhe spiral element which is i'ormed by cutting is capable of being pressed or flexed to place one of the bands or rings thereor'l within the other. As will readily Vbe understood by reference to the drawing' the spiral element is provided with a shoulder 2 thus really providing` two spiral bands which are integrally united; one of which bands is adapted to be placed within andrencircled by the other.

As shown in 1, the adjacent edges oi' the spirals are integral; and as shown in Fig. 2, the spiral element is formed by cutting` sufcient material from the edge there of and from between the spirals to produce a spiral member or element which is of uniform width throughout its length. This may be done by taking from the outer edges oit' the blank, material equal to the width of the slot.

After the spiral element has been formed as described above? or in any other manner, the two integrally united bands or rings are placed one within the other and while in that position. or adjustment they are subjected to treatment in order to set the material in the changed shape, so that when the pressure is removed the product that remains will consist o'l a ring composed of an outer band and an. inner band which are integrally united at one point and which have sol their opposite Vends free in order to permit proper functioning` of the device as a piston ring. Y As will be understood by reference to Figs. 7, 8 and 9, one end only of the inner. band is integrally united with the opposite ment to set the material thereof in the shape 1 in Figs. 3 and 7 the inner and outer bandsV desired.

In whatever manner the materiai; is treated the surfaces of the ring are ground off or finished either before or after the treatment is complete. Y

As shown in Figs. 3 and 7 the ring comprises an outer band or ring 3 and an inner band or ring 1 integrally united with each other 'at their opposite ends by overlapping connection 2. In the form of the ringshown are of equal width and approximately equal radial thickness throughout the circumference of the ring; though this construction maybe variedtas will be understood by referen'ce to some other forms of the invention illustrated.

The ring shown in Figs. 1 and 17 consists of an outer band 5 and an inner band 6 integrally united at 2 as in the case of the ring shown in Fig. 3. The outer band 5 is formed with an` inwardly extending flange 7, the inner periphery of which lies in lthe same plane with the inner periphery of the band 6; and the inner band 6 is provided with a circumferential flange 8 the outer edge of which is in the same annular plane with the surface of the band 5.

The formv of ring illustrated in Figs. 5 and 16 is composed of anouter band 9 and an inner band 10 integrally united at 2, and having a circumferential groove 11 in which the'outer band is seated. The groovell is of sufficient depth to receive the outer band so that the periphery of the outer band is in the same plane with the periphery of the in-V ner band at each side of the groove.

The ring illustrated in Figs. 6 and 15 is composed of an outerV band 12'and an inner band 13 integrally united at 2as in the case of thegoth'errings described. The outer band 12 Yis' of less width than the inner band,rthe

Vlatter being formed with a circumferential flange 1&1 at one'side Vof the band 12, having its edge in the saine annular plane with the.V

periphery of the band 12. j The form ofring illustratedin Figs. 8

and 141 is composed of an outer band 15 and an. inner band 16 integrally united at 2. rIhe bands 15 and 16 have matching inclined surfaces which Contact with each other as shown in Fig. 11so that there is a slight tendency for the inner band to press the outer band laterally toward one side, thus closing the groove in the piston in which th ring may be mounted.

VVarious other forms of the invention may suggest themselves from the forms disclosed and Ido not confine myself to the specific formation shown in the drawing. It will be 'apparent also that various forms or joints may be provided for closing the space be- A tween the end of the outer band and the ad- 1 which the outer ring has an angular terminal 19 adapted to cooperate with a similarly shaped wall on the shoulder 2.- The form of the joint illustrated in Fig. 12 includes a notch 20 in the end of the outer band and a projection 21 on the shoulder 2 adapted to he received within the notch 20 and thus close the space and prevent the passage of gas when the ring is compressed within thecylinder. Y y

`.It is obvious that various other forms of joints may be provided in order to prevent the passage of gas or steam between the end of the outer band or ring andthe adjacent shoulder.

Itis well known that a piston ring mustA be of a diameter larger than the internal diameter of the cylinder in which it is to be used. In the manufacture of piston rings heretofore in some cases the rings have been made from blanks of a diameterwhich is too small for the cylinders in which it is desired to use the rings. In such cases the rings are expanded to the desired dimensions and set in their expanded shape so that they will impart the Vnecessary pressure against the cylinder walls in the operation ofthe piston. In other cases rings have been made Vfrom blanks of the desired size so that it is unnecessary to expand the rings.` It is obvious that rings may be manufactured ineither way, and still embodythe principles of my invention.

lVhat I claim and desire to secure by Letf.A

other, and an integral connection uniting said coils and having a radial thickness equal to the combined thickness of said coils.

2. A piston ring, composed of a single piece of homogeneous metal and comprising,` an inner annular band, an outer annular` band of the same Width as the inner band encircling` the inner band, and an homogeneous connection having a radial thickness equal to the combined thickness of said two bands uniting` one end of the inner hand with the opposite end oi the outer band and having; its outer surface on the saine radius of curvature as the outer surface oi' the outer band.

A piston ring comprising a spiral, havinp; an inner convolution and an outer convolution united by an integral connection,

. the cross section of said connection conforming` to the combined cross-sections of said convolutions, said convolutions having a tendencyv to expand radially, each of said convolutions being or" trapezii'orln cross-section and including,` a side in contact throughont its length `with -the corresponding' side of the other convolution.

4. A piston ring` Comprising a spiral, having an inner convolution and an outer convolution united bv an integral connection, the juxtaposed faces of said convolutions being` beveled and in contact with each other throughout their lengths.

5. A piston ring; comprising` a spiral, having an inner convolution and an outer convolution united by an integral connection, the cross-section of said connection conforming to the combined cross sections of said convolutions, said convolutions having' each a bevel face, said beveled faces contacting throughout their lengths.

HARRY S. FRANK. 

